Transferring a number mid-contract?

[Guest sponge]

Is it possible to take out a new contract, and hence get a new number, then a few months down the line, when the old contract expires, obtain the PAC and change the new number for the old one?

I'm not sure that was explained well, so this is the scenario:

I have a contract that has 4 months to run, but I want the c500 now. I also want to be able to keep my existing phone number.

If I take out a new contract to obtain the c500, I will get a new number.

In 3.5 months when my old contract expires, can I get the PAC and ask Orange to change my (new) number to the (old) preferred number?

I could just wait a few months, but I am very impatient. :)

[Guest ferryrich]

I was speaking to Orange yesterday and they told me that you can't use PAC except to change network.

Now, I have an o2 PAYG SIM which was free and can easily transfer my number to that, however I was told by Orange that I could only transfer my number back to Orange after 3 months AND only at the start of a contract. I'm not sure thats the truth, so I'm going to ask in the shop today. If in doubt, ask Ofcom cos you can complain through them if your network refuses to do it.

Just to clarify - You can't port your number within a network, you have to change.

[Guest sponge]

I didn't mention it in the original post as I didn't want to complicate it with too much information. But the 'existing contract' is O2 Line Advance, in my name, but which my girlfriend uses. So it would be a cross-network port.

Oh, by the way - what did they say in the shop?